The present invention is directed to a method of and to apparatus for cutting, drilling and similar erosive working of a rock, ore, coal, concrete or other hard object, using multiple-jet discharges of a pressure-fluid medium.
Methods and apparatus of the character indicated are known from German patents 3,739,825 and 3,915,933. In this connection, it is also known from German patents 3,410,981 and 3,516,572 to provide nozzle heads with a plurality of nozzles. And it is further known from German patents 3,422,311 and 2,607,097 to mount nozzle heads so as to enable them to be pivoted on a crankshaft.
The above-mentioned methods and apparatus have already proven their worth since it is possible thereby also to work elongate and narrow slots, boreholes and similar holes, for instance from hard rock, and the known apparatus is of relatively narrow and elongate configuration.